Li-Ion Cathode Sulfonate Coating for High-Temperature Cycle Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium ion batteries experience capacity degradation due to electrolyte decomposition during repeated charge and discharge cycles, especially at high temperatures.
Innovation Solution
Incorporation of a sulfonic acid compound containing a sulfonate anion and a Ni cation into the electrode, along with a positive electrode active material layer composed of LizNi(1-x-y)CoxMyO2, where 0≤x≤0.40, 0≤y≤0.40, 0.90≤z≤1.20, and M is Mn, V, Mg, Mo, or Al, to form a solid electrolyte interface (SEI) film, reducing electrolyte decomposition and maintaining high capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If charge and discharge are repeated at high temperature, then battery capacity decreases due to electrolyte decomposition, but increasing the coating film thickness to prevent decomposition increases internal resistance
Solution Approach 1:
The invention changes the chemical composition parameters of the coating film by incorporating specific sulfonic acid compounds with sulfonate anions and Ni cations in controlled ratios. This compositional parameter change enables the film to provide effective protection against electrolyte decomposition while maintaining ion permeability, thus preventing capacity degradation without significantly increasing internal resistance.
Solution Approach 2:
The invention creates a composite coating film structure combining sulfonic acid compounds, sulfonate anions, and Ni cations on the electrode surface. This composite material approach forms a multifunctional protective layer that simultaneously provides electrochemical stability, prevents electrolyte decomposition, and maintains lithium ion conductivity, resolving the contradiction between protection and resistance.
2Duration of action of stationary object
If a coating film is formed on the electrode surface to prevent electrolyte decomposition, then cycle characteristics improve, but the complexity of the electrode structure increases
Solution Approach 1:
The invention applies a preliminary protective action by forming the sulfonic acid compound-based coating film on the electrode surface before battery operation. This pre-formed protective layer prevents electrolyte decomposition from the outset, improving cycle characteristics without requiring complex structural modifications during battery operation or assembly.
Solution Approach 2:
The coating film composition, including sulfonate anions and Ni cations, is designed to self-organize and form a stable protective structure on the electrode surface. This self-organizing capability reduces the need for complex external control mechanisms or additional structural components, simplifying the overall electrode structure while maintaining improved cycle characteristics.
3Reliability
If lithium sulfonate is added to negative electrode slurry to improve cycle characteristics, then storage characteristics improve, but the manufacturing precision of the coating uniformity becomes difficult to control
Solution Approach 1:
The invention optimizes the concentration parameters of sulfonic acid compounds and controlling the ratio of sulfonate anions to Ni cations in the slurry. By precisely controlling these compositional parameters, the invention achieves uniform coating formation on the electrode surface while maintaining improved storage characteristics, thus resolving the manufacturing precision issue.
Solution Approach 2:
The invention ensures that the sulfonic acid compound-based coating is uniformly distributed across the entire electrode surface, creating consistent local properties throughout. This uniform distribution of protective components improves storage characteristics while maintaining manufacturing precision through controlled application processes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively suppresses electrolyte decomposition, maintaining high capacity and reducing resistance in lithium ion batteries during repeated charge and discharge cycles, even at high temperatures.
Implementation Method 1
Incorporation of a sulfonic acid compound containing a sulfonate anion and a Ni cation into the electrode, along with a positive electrode active material layer composed of LizNi(1-x-y)CoxMyO2, to form a solid electrolyte interface (SEI) film, reducing electrolyte decomposition
Data Source
AI summary
An electrode for lithium ion batteries, containing a sulfonic acid compound which contains a sulfonate anion represented by the following Formula (1) and a Ni cation, R—SO3− (1), in the Formula (1), R represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group or the like, in which the electrode contains a positive electrode active material layer, and the positive electrode active material layer contains, as a positive electrode active material, LizNi(1-x-y)CoxMyO2, in which 0≤x≤0.40, 0≤y≤0.40, 0.90≤z≤1.20, and M is at least one element selected from the group consisting of Mn, V, Mg, Mo, Nb, and Al.